Electrode for spark-plugs



J. V. OSTERHOUT ELECTRODE FOR SPARK PLUGS. APPLICATION FILED DEC.8. 1919.

1,373,907. Patented Apr. 5, 1921;

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roan v. os'rnanou'r, or BRIDGEPORT, conmcrrcur.

nnneraonr. ror. SPARK-PLUGS.

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specification of Letters Patent.

Fatented Apr. 5,1921.

- Application filled December 8, 1919. Serial No. 343,152.

To all whom. it may concern:

Be it known that 1, Joan V. Os'rnnrrou'r, a citizen of the United States, and a resident of Bridgeport, in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Electrodes fo Spark-Plugs, of which the following is a specification.

Where an internal combustion engine is relied upon to furnish power in circum-- stances which do not admit of temporary failure, it is necessary to insure unfailing efiiciency in the ignition of the fuel. In particular, the internal combustion engines of aeroplanes mustfunction without lapse;

The existence of ignition trouble in such motors is very frequently a vital matter. Itv

is therefore essential that the igniters for spark plugs used in such engines be unfailin in their operation.

%park plugs used in engines of the above character may be of several types. For example the central electrode may be lncased in a arge insulating core which extends over substantially the entire length of the electrode and leaves only the firing point exposed. The intense heat existing during normal operation in the engine cylinder ultimately causes the fracture of this porcelain. Such fractured bits'of material, if falling in the explosion cylinder will score its sides and interfere with its successful operation. Even though the core is not broken by the heat, deposits of carbon are readily formed upon it and short circuit the current, thus defeating the ignition function.

Another type of electrode avoids the use of long insulating cores, and substitutes therefor a short insulating corewith a long ex osed portion of the central electrode. In this latter case the rod, of which the central electrode is com osed, is subject to deflection and distortion by the heat and other conditions in the internal'combustion engine. There results a material variation in the ap between the central or primary electro e and the secondary electrode. This renders indeterminate and uncertain the uniformity of igniting sparks.

My invention is directed to the provision of a central electrode in a spark plug which shall retain the advantages of t e rigidity found in an electrode sheathed for the greater part of its length by an insulating core; and the freedom om fouling, short-circuiting and breaking, as in the type last described.

- bodying may It is a further object of my invention to provide a central electrode which will hold its position definite regardless of variations in temperature or other surrounding conditions.

Other objects of my invention will be evident from the following description and drawings, in which Figure 1 is a longitudinal view, partly broken away, of a spark plug. and its cenv tral electrode;

and

Fig. 3 is an end view of the same.

The customary form of spark plug em my invention is shown to consist of a acket 4 having a screw-threaded sleeve 5 integral therewith. The extremity of the sleeve which projects within the explosion chamber of the engine carries the secondary electrode 6 arched in toward the center of the sleeve.

A nut 7 screws into the opposite end of the jacket 4 and looks into close engagement with the latter, an insulating core 8. This core 8 may consist of porcelain or other insulating material. The inner end of the core 8 carries the shoulder 9 and the short tapering extremity 10. The shoulder 9 is locked in tight engagement with the internal shrzuder 11 of the jacket by means of the nu The central electrode of improved form.

passes through the core 8 and consists of the rod 12 screw-threaded as at 13 to receive a connection 14 with the ignition circuit. Surrounding the lower portion of the rod and abutting against the end of the tapering projection 10 1s a collar or disk 15. The lower end 16 of the electrode is cylindrical for a short distance as illustrated at 17. From the upper portion of the cylindrical part 17 to the outer edge of the collar 15 are a plurality of longitudinal fins or ribs 18. Each rib has a knife edge 19. The ribs and collar are preferably formed integrally with the rod 12, although it is obvious that they be constructed thereon if desired.

With the rod 12 mounted in the core 8 Fig. 2 is a view of the central electrode and extending intothe. explosion chamber so The electric current passes through the rod l2,ju1nps the gap by means of a spark and causes the explosion in the chamber. The reduced portion ofthe core 10 and the extended ribs 18 will not be affected by the high degree of heat and other conditions. The ribs 18 for rigid supports to retain the central electrode 16 in its predetermined position regardless of any tendency to Warp. While the electrode is held in a rigid position there is no exposed insulating surface to become carbonized. There is no tendency of the short insulating porcelain 10 to fracture or become deteriorated in use.

The particular embodiment of my invention shown is, of course, susceptible of con- 'siderable variation Without departing from the spirit of my invention, and. it is to be understood that many changes may be made by those skilled in the art, Within the scope of the invention as defined in the appended claims.

l/Vhat I claim is:

1. In a spark plug including a jacket, a lock-nut and a core, an electrode mounted in said core, said electrode having an extended bearing against the surface of the core and being braced against distortion.

evaeor 2. In a spark plug including a jacket, a lock-nut and a core, a relatively long narrow rod constituting an electrode mounted in said core, a collar on the electrode and abutting against the core, and longitudinal tapering ribs extending from the collar to- Ward the end of the electrode.

3. In a spark plug including a jacket, a lock-nut and a core, an electrode mounted in said core, a collar on the electrode and abutting against the core, longitudinal ribs extending from the collar toward the end of the electrode, and a second electrode mounted on the jacket.

4. As an article of manufacture, an electrode for spark plu s including a rod, a median collar integra therewith and a plurality of tapering ribs surrounding said rod.

5. As an article of manufacture, an electrode including a rod, a median lateral enlargement thereof and bracing means extending from said enlargement outwardly along the rod.

In testimony whereof, I hereunto afiix my signature.

JOHN V. OST'ERHOUT. 

